Apparatus for milling screw-threads.



A.. HOPKINSON.

APPARATUS FOR MILLING SCREW THREADS.

APPLICATION. FILED MAR. 28. I9II. 1,292,781. Patented Jan. 28,1919.

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APPARATUS FOR MILLING scHEw THREADS.

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APPARATUS FOR MILLING SCREW THREADS.

APPLICATION FILED MAR 28,191?. l1,292,781. Patented Jan.28,1919.

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A. HOPKINSON.

APPARATUS FOR MILLING SCREW THREADS.

APPLICATION FILED MAR.28.\9|1.

1,292,781. Patented @11.284919 l0 SHEETS-SHEET 4- A. HOPKINSON.

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A. HOFKINSON.

APPARATLIS FOR MILLING SCREW THREADS.v

AEPLICATION FILED MAR.28.1917.

1,292,781. Patented Jan.28,1919.

l0 SHEETS-SHEET 6- @Marne/15A A. HOPKINSON.

APPARATUS FOR MILLING SCREW THREADS.

APPLICATION FILED MAR. 28. I9I1.

Patented Jan. 28, 1919.

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APPARATUS FOR MILLING SCREW THREADS.

APPLICATION FILED MAR. 28. 1911.

Patented Jan.- 28, 1919.

l0 SHEETS-SHEET 8- A. HOPKINSON.

APPARATUS FOR MILLING SCREW THREADS.

APPLICATION FILED MAR 28,1911.

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Patented J an. 28, 1919.

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APPARATUS FoR MILLING SCREW THREADS.

I APPLICATION FILED MAR 28,1917. 1,292,781 Patented Jan. 28, 1919.

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ments in Apparatus vfor Milling Threads, of which the following is a speci;-

; srn'rns PATENT oi'iiiroli.

ALFRED Hopkinson, or HYDE; nireLnND.,

Arf/ramos ronmnmmci SCREW-THREADS.

Toy all whom imag/concern; l

y Be it known that 1,.AuRED llorimasori, ay British subject, residin at Cree Cross, Hyde, county of Chester, ngland, have invented certain new anduseful Im rolve-v crewtlcation.

-The invention relates to apparatus for milling internal surfaces in which the milling tool is carried on a rotary `spindle which is eccentrically or radially adjustable to bring the tool'to the surface of thework, the tool havingl a secondary rotary and longitudinal movement imparted thereto to cause it to traverse the surface of the work.

The invention consists in the particular construction and .disposition of the parts which render itr especiallyv applicable'for milling internal screw threads, said' part comprising a` cylindrical casing,- a rotary cylindrical sleeve fitted within the `casing* and bored eccentrically, a tool carrier placed eccentrically within the rotary sleeve, a worm or toothed gear allixed to the rotary sleeve. by-which it is rotated and a screw mounted upon or connected with the sleeve so as to move the latter forward during its rotation.

The invention will be fully described with' reference to the accompanying drawings.

Figure 1 is a side elevation of one form of the apparatus. i

Fig. 2 is an end elevation.

Fig. a is an enlarged detail longitudinalV section. p

Fig. 4 is a transverse section of Fig. 3.

Fig.l 5v is a side elevation of another form of the apparatus. y. if

Fig. 6 is a longitudinal section.

Fig. 7 is an end elevation.

Fig. 8 is ,a longitudinal section showing a direct drive for the tool spindle.

Fig. 9 is a longitudinal section of another forni-of the apparatus showing the backing olf motion.

Fig. 10 is a' front elevation.

f Fig. 11 is an end elevation showing a chain drive. 'l

Fig. 12 is an end elevation showing a gear drive.

Specification of Letters Patent.

` Patented Jan. 28, 1919. Appncatin and umn z8, iai?. serian No. 158,053.

Fig. 13 is a longitudinal section of a further modified form of apparatus.

l Fig. 14 is a front. elevation drawn to anI enlarged scale. 55

The apparatus 'is constructed with a bed of any suitable construction upon'which are mounted a head stock A to carry the appa-g' vratus and a head stock or cradle A2 to carry and center the work (a projectile being shown in osit'ion).

The mi ing tool B,which is of ordinary I, form for either cutting screw threads or for plain milling, is mounted on a rotary spindle b, and for screw cutting is provided with annular grooves, the widths-of which are equal to the pitch of the thread to be cut.

The head stock A is formed vwith a cylindrical casing A formingbearings for a cylindrical carrier or sleeve Cy free to rotate therein, and fitted with '.a worm wheel c gearing with a worm c by which it is slowly rotated'the worm being driven either by a pulley C or by a hand wheel C2, both of 1the latter devices Ibeing shown in Fig. 2. Instead' of a worm and worm wheel other forms of gearing may be employed. The

cylindrical carrier C is turned or bored into and out 'of action. A forward `feed is imparted to the carrier orl sleeve C by a screw as it rotates (see Fig. '7.)

' In the form shown *in Figs. 1 to 4 and 8 a'rin-g E is fitted to the carrier or sleeve C and isprovided with a eripheral thread t'o enga ta corresponding y .threaded ring or nut which may be mounted either on the cylindrical casing A as in Fi 3;' or on a. handwheel G asin Fig. 8. e pitch of the thread on the ring E Vis equivalent to Ethat required on the work and as the saidcarrier vC rotates within the casing A the l lution the thread on the work is complete.

The milling cutter B ,and its spindle b are driven by a pulley P direct on the spindle b as in Fig. 8, the beltl being kept tight Aat ' cam rotates relative movement of the two is so Fig. 3.

as the position 'of the spindle altersby a weighted or tension pulley (not shown) pressing against the belt to take up any slack therein, or the spindle b may be driven by universal clutch b between it and a spindle b2 on which the .pulley P is mounted as in In the form shown in Figs. 5, 6, 9, and 12 and 13, the cylindrical casing Ais similar .to that already described with a worm c .mounted therein to rotate the worm wheel 0,'the worm wheel c being attached by screws or 'otherwise'to thel rear of the carrier C. The carrier C is fitted with screws H. H H2 by which the inner or eccentric carrier D can be adjusted or`canted to compensate for any spring in the cutter B or its spindle,

The innerer eccentric carrier D is constructed in two parts pivoted or hinged at d to lallow of the adjustment by the screws H H H2 inserted in the carrier C. At 'the rear end of the carrier C a spindle" e is affixed' and to the spindlea screw E2 is tted to rotate with it, engaging in a corresponding threaded ring or nut Es the nut being fitted to the bearing a2 of the head stock A. The screw E2 and nut Es are removable and replaceable for dierent pitches of threads to be cut. *The pitch of the screw E2 is equivalent to that required 011l the work'and as the carrier C rotates within the casing A it and the milling cutter B are fed forward and when the carrier has rotated onefrevolution the thread onl the work is complete. The milling cutter B and spindle b are driven by a pulle P loose on the spindle e through a train o gears p p p2 p. 2

In any form of the a paratus the cutter spidleJ may `be driven by a iexible shaft or other "exible drive and the eccentric carrie-r D may be rotated within the carrier C by worm or other gears to give the depth of cut. For cutting tapsl a -centering or supporting device may be applied to the carrier D, and for cutting dies and taps an oscillating movement maybe given `to the lcarrier -D within the -carrier C to eect a relieving or backing 0E thereon.v This is effected lby a-rotary cam K carried by an arm l: on the sleeve C and engaging an arm 1c aixed to the carrier D whereby as the e'ected and the cutter moved to and from the work, The cam K is rotated by a pinion k2 engaging a stationary toothed wheel K fixed to the casing A.

Although primarily designed for cutting internal screw threads in shells the apparatus maj7 beemployed for 4cutting internalrecesses, a cutter rB of any desired shape being used, or it may be used for tooling orv truing internal surfaces, or for cylinn` drical external'surfaces. For plain surfaces it may be used either with Vor without the feed screws E. f f

In operation the work is clamped in a stationary holder Wise or clamp or other centering device according to the shape or' nature of the article, and held stationary,

and the head stocks are adjusted to bring the work up to the cutter or .the cutter up to the work, the cutter being nearly in contact with the surfacc,the tool is set in motion and the eccentric carrier D rotated within the carrier C to give the desired depth of cut, the two carriers are then clampedv or locked together and the worm c setin motion thereby rotating the two carriers, and fthe cutter B travels around the work (either internal or external thereto) until it has completed a revolution, the rotation of the carrier C by means of the screw- E rotating within the lnut E givinglthe desired fee What l claim as my: invention and desire -to protect by Letters Patent is 1. An apparatus for milling or cutting ternal or external cylindrical surfaces, comprising an internally cylindrical xed ca sing, a rotating cylindrlcal sleeve carrier eccentrically bored and fitted in the casing, a bush rotatably fitted in the sleeve carrier andprovided with bearings eccentric to the periphery of the carrier and also having an eccentric bore, a tool' spindle fitted in the bore'of the bush and having means for ro tating the same, means for slowly rotating the cylindrical sleeve carrier, the means\for rotating the spindle and carrier being mdependent, and a screw means fory imparting a forward feed movement to the sleeve carrier whereby when the Acarrier and bush riphery of the carrier and also having an eccentric bore, a tool spindle fitted in the x bore of the bush andprovided with means for rotating the same, means for slowly rotating the cylindrical sleeve carrier, the

means for rotating the cylindricalsleeve carrier being independent of the meansj for rotating the tool spindle, and a screw connected to the sleeve carrier and engaging a fixed nut to feed the said carrier and bush iIn testimony whereof I have hereunto set forwardly as they rotate whereby when the my hand in presence of two subscribing witcarrer and bush. have made one revolution nesses.

the tool spindle and tool carrier is fed for- ALFRED HOPKISON. 5 Ward a distance equivalent to the pitch of Witnesses:

the out made by the tool on the Work in I. OWDEN OBRIEN,

one revolution of the said sleeve and bush. GEO. H. OBRIEN. 

